While they are very nice little creatures that are always happy to be petted, the Hellions are really, really dumb.
It's true, they eat ribbons and fall off furniture and are generally stupid in the ways that all cats are stupid. However, they occasionally do something really epic that reminds me just how much intelligence they lack. The first clue that we might be dealing with impaired animals came the day Z coaxed Grey-Hellion into the shower.
A regular-dumb cat might get coaxed into the watery torrent once, but it takes exceptional-dumb to be coaxed in again moments later.